The failure of fatigue-limited components in various types of systems often leads to undesirable or tragic consequences. For instance, the failure of a critical component of a jet engine during the operation of the engine may result in the loss of human life or other tragic results. Directed energy measurement techniques have been developed to test these critical components, detect defective components, and prevent undesirable situations from ever taking place.
Typically, directed energy measurement techniques involve directing energy at a part under test and sensing the resulting diffracted energy and/or attenuated energy. If a diffraction technique is used, the resulting sensed diffraction peak is interpreted to arrive at a measurement of a material characteristic. With energy attenuation techniques, the amount of energy that is absorbed by the material is determined and this amount is used to determine the same or additional types of material characteristics.
The material characteristics of the part under test often are related to stress. For example, stress may be determined along or under the surface of the part under test. Additionally, the error present in measuring stress (stress error) may be calculated. If multiple sensors are used to detect diffracted energy, the ratio of two stress measurements, as determined at the two different sensors (intensity ratio), can be determined.
Another characteristic that can be determined is the average peak breadth of the stress measurement. This is usually defined as the width of the Gausian distribution of stress as measured at a sensor. Average full width half magnitude (FWHM) (average full width at half maximum of the Gausian function for stress as measured at a sensor) may also be determined.
The shear stress can also be determined. Further, a stress tensor may be determined by taking multiple measurements of stress and determining the magnitude and direction of the stress in the part under test. An error tensor, relating to the magnitude and direction of error in the stress tensor, can also be calculated. Stress may also be determined as a function of position in the x-direction or as a function of position in the y-direction. The maximum stress in any direction (equivalent stress) may also be obtained. Other characteristics can also be determined.
After the material characteristics have been determined, it is often desirable to display this information to an operator of the measurement equipment. For instance, the values of these characteristics can be mapped into two or three-dimensional graphs and displayed to the operator using a video terminal. However, present systems and methods only display a graph relating to a single material characteristic of the part under test.